Sulfur-free oxo alcohols



Jan 22, 1957 F. B. JOHNSON ET AL 2,778,859

SULFUR-FREE oxo ALcoHoLs Filed May 27, 1953 .ws-OPPO@ Olmi-IWW' Frank B. Johnson l nited States Patent O SULFUR-FREE X0 ALCOHOLS Frank B. Johnson, Warren M. Smith, and `lames E. Moise,

Baton Rouge, La., assignors to Esso Research and Englneering Company, a corporation of Delaware Application May 27, 1953, Serial No. 357 ,782

4 Claims. (Cl. 260-638) -The present invention relates to the preparation of oxygenated organic compounds from olens by reacting the latter with CO and H2 in the presence of carbonylation catalysts. More specifically, the present invention relates to the preparation of alcohols of a high degree of purity suitable for employment in processes requiring quality grade alcohols, such as in the manufacture rice ventional conditions including temperatures and pressures of the same order of magnitude as those obtaining in the first, or carbonylation, stage. Various known types of catalysts, such as nickel, molybdenum, tungsten, and their oxides or suliides, supported or unsupported, may be employed.

The liquid product from the primary hydrogenation stage is worked up by distillation to separate the desired alcohols from side reaction products, such as hydrocarbons and Unreacted materials, as Well as condensation products.

One of the largest and most important uses developed for the synthetic alcohol product is that of producing esters suitable for plasticizers, by reaction with aliphatic, alicyclic, 'and aromatic acids and anhydrides, such as phthalic, adipic, maleic, and the like. In particular the C'z-Cio alcohols prepared by oxonation and hydrogenation of the corresponding Cra-C9 olefin are especially suitable'for the manufacture of ester plasticizers and particularly for use in clear plastics. f

These esters are generally prepared in standard type esterication equipment employing reactors made of stainless steel or other corrosion-resistant metal or alloy. It has been found in many instances that the ester product thus produced was deficient as to the standards required for plasticizers, particularly as to such propdissolved in it salts and carbonyls of the catalyst, is I treated in a second stage to cause removal of the metal compounds from the aldehyde product. Thereafter, the catalyst-free product is generally hydrogenated to the corresponding alcohol. l

This carbonylation reaction provides a particularly attractive method for preparing valuable primary a1- cohols which find large markets particularly as intermediates for plasticizers, detergents and solvents. Amenable to the reaction are long and short chained organic compounds having olelinic unsaturation in the molecule, such as straight and branch chained olelns, olenic oxygenated compounds, olelinic polymers and the like.

The catalyst in the lirst stage may be added as the olefin-soluble salt of cobalt, such as cobalt oleate or naphthenate. Also, aqueous solutions of cobalt compounds, or slurries of oil-insoluble forms of cobalt may bev-employed. Inasmuch as the active catalyst is probably cobalt hydrocarbonyl, most forms of the metal may be employed as catalyst, for they are converted into the active catalyst species in the course of the reaction.`

The synthesis gas mixture fed to the first stage may consist of an Hz/CO ratio of 4 to 1 to 1 to 4. Preferably, however, these gases are present in about equimolar ratio. The conditions for reacting Hz and CO vary somewhat in accordance with the nature of the olellin feed and form of catalyst; generally, the reaction is conducted at about 2000-4500 p. s. i. g., preferably at Z500-3500 p. s. i. g., and at a temperature in the range of 'about 250-450 F., preferably 300-375 F.

Following the carbonylation stage the aldehyde product, containing in solution considerable amounts of dissolved catalyst, is generally treated at elevated teml peratures in the presence of a gas or vapor,vsuch as H2 or steam, to decompose the carbonyl to an oil-insoluble form of cobalt and drive off the CO formed. Thereafter, the aldehyde produ-ct is freed of suspended catalyst and is passed to a hydrogenation zone for conversion to l'the alcohol. y

lThe hydrogenation stage may be operated at conerties as color, odor, and weathering qualities-of the plasticized resins. In particular, it was found that 'the color of the ester product formed by continuously recycling alcohol progressively increased and rapidly darkened, making a large proportion of the ester products completely unsuitable for plasticizing purposes where a colorless or clear plastic is required. Thus in typical commercial alcohol recycle esterica'tion operations, wherein an alcohol is esterilied with phthalic anhydride,

, a l-20% molal excess of alcohol, based on anhydride,

is employed. Unreacted alcohol is stripped from ester product under reduced pressure and blended with fresh alcohol for return to the esterication zone, and it is this alcohol which presents the color problem.

One of the most important class of alcohols suitable for preparation of plasticizers is the octyl alcohols. These have hitherto been supplied on a commercial scale mainly by such comparatively costly procedures as aldol condensation of butyraldehydes, followed by dehydration and hydrogenation of the unsaturated octyl aldehyde. However, with the introduction of the carbonylation, or aldehyde synthesis reaction, it was found that these octyl alcohols could readily be prepared from various olenic C7 fractions commercially available. Olefn fractions readily available are principally those derived and resulting from the processing of petroleum distillates and residua. Thus, available on a large scale are olefin fractions from thermal and catalytic cracking processes, either directly or from polymerization of olefins derived from these processes. These sources all produce, in large supply, olen fractions con-taining substantial amounts of heptenes.

One 'of the most promising sources of supply of hep- 'tenes is the olefin polymerization processv wherein low molecular weight oleiins, such as propylene and butylenes, are polymerized in the presence of a catalyst, such as phosphoric acid on a siliceous carrier, to produce a large 'variety of olenic products. Many refinery light end streams contain appreciable amounts of olelins, and most suitable are the C3 and C4 fractions for this polymerizing process.

Desirable as it is to utilize these oletins from petroleum sources in the preparation of plasticizing alcohols and esters, it has been found that the alcohols thus prepared larly susceptible to the defect hitherto pointed out, in that the alcohols thus formed tend rapidly to build up color bodies in the course of `esterilication.

It has now been found that the color forming tendencies of the alcohol product are intimately associated with extremely minute amounts of sulfur compounds presentin the olefin feed, and particularly in the feed to the polymerization zone wherein theC3 and C4 streams are copolymerized. The feed streams frequently have ,sulfur contents of 0.1% and higher and, in the prior art, where these vp olyrnerized khydrocarbons were to be used as gaso- -lin'e lwith lor without a subsequent hydrogenation treatment, it was lsufcient to reduce the sulfur level to, say v0.03 -to 0.08%. However, it "has 'been now determined that sulfur in amounts Vas low as 20 parts ,per million, or i002%,-in the -finished alcohol product, VLis suicient to make'thelatter completely unsuitable for esterifi'cationpurposes.

In general, A'the entire content 'of the sulfur which is present -in the synthetic fOXo alcohols is in the form of organically combined sulfur. Although the exact type of organlc-impurity in which thesulfuroccurs has not been determined fully, iin general, it is deleterious in all forms. However, the form of sulfur changes `in the course of the .process frcmthe introduction of the feed to the polymerization zone to the iinal alcohol distillation process.

*It I1s Za difficult and expensive process to remove undeslrableproducts lpresent in thecar'oonylation alcohol, either .directly from the latter or .from the feed streams 4to the .carbonylationrprocess Thus, caustic washingof the crude ,alcohol rproduct to remove vacidic constituents leaves untouched such non-acidic sulfur compounds as disuldes. To'employ a substantially sulfur-free 'feed stock, though .des1rable, severely vlimits the availability of suitable feed Lstock for the process.

r`In flnfieftherefore, extremely small amounts of sulfur .appearing inthe alcohol product, to the extent of more than about 10-15 parts per million, when this is to be used for plasticizing purposes, Aplays an important role in dcgradlng the resultingcster and making it unfit yfor use, ;andi this sulfur is introduced principally with the olefin Thus, in a commercial plant operation, manufacturing 'octyl alcohol from a C'z oleiin fraction which was in turn prepared from copolymerizing propylene and butylenes, it 'Twas @found that a 14,000 gallon portion of alcohol produced containedonly. l2 parts per million of sulfur. Yet on lestcrilication, an .ester color of 0.35 was produced. Even `with this extremely small amount of sulfur, the alcohol'was thus unsuitable for use as a plasticizer intermediate for later esterication. The ester color is a .measure of .the optical density of the phthalate ester as produced under prescribed conditions, and is expressed in sof colorabsorbency of the ester at a standard wave `length 4of light, ak high `value indicating a darkened, low quality ester product; for Visooctyl phthalate, a' wave -lengtlftof 4470 used, and to be satisfactory, fthe ester color may not behigher than 0.15.

VIn accordance with the present invention, high'quality alcohols .suitable for plasticizing purposes are obtained by employing as a feed to the aldehyde synthesis reaction zone, one substantially completely free of sulfur, i. e. one that contains less than v25 parts per million sulfur. Aln a prefened embodiment of the present invention, such a :feed .preparediby removing thoroughl.l organic sulfur lpresent in refinery streams passed to a light ends polymerfi'zation zone. Thus, refinery streams containing Cs and C4 olefius may be passed through a caustic scrubbing system to reduce the sulfur content of the respective streams to less than l parts per million. it is particularly advantageous to remove sulfur at this stage rather thansubsequently in the process, for the sulfurpresent in the reinery light ends streams yis present mostly as `mercaptan sulfur. lf not removed prior to passage to the polymerization zone,-the sulfur tends to become converted in part `to disuliides and oxygenated sulfur compounds,

which are much more difficult to remove. It has been found that the alcohols produced by oxonating Cr olefins thus produced, i. e. by removing sulfur from the feed to the polymerization zone, formed in turn octyl esters of completely satisfactory color characteristics.

lt will be recognized that though oleiins boiling in the gasoline range have been hitherto treated to decrease sulfur or render ytheir sulfur content inactive, i. e., by Doctor Sweetening, such decrease or inactivation is not adequate for preparation of feed stocks .suitable .as intermediates for the production of lplasticizing alcohols. The upper limit of sulfur tolerance of la gasoline is 1000 parts per million; if the sulfur is in the form of a disultide, it need not be removed at all. But for the alcohol synthesis process, the tolerance limit is less than 25 parts per million in the feed, to produce an alcohol product containing less than about l0 parts per million.

The present invention and its application will best be understood 'from the more detailed description hereinafter, wherein referencewill be had to vthe accompanying drawing, which -is a schematic Irepresentation of .a system ysuitable for carryingloutapreferred embodiment .of the invention.

'Referring-now tothe drawing, -Cs and C4 Volelin streams whichhave been previously ifractionatedin suitable equipment in a light ends-plant, and which may .have resulted from catalytic `or thermal Acracking of gas oil or 4other suitable material, are passed .through lines .l and 2 to caustic scrubbers 3 and d-respectively. The `streams .are preferably 4low in isobutylene content, and for this purpose, the butylene stream may .first have been :extracted ywith suitable agents to .reduce orremove iso-Ci, such as 60% H2 S04, cresol, andthe like. The light ends astreams contain a greater or smaller amount of sulfur depending `upon the nature of the ycracking stock. Average composiftion may be up to 0.1%.

In .one embodiment, the scrubbers measure 61/z-X30 :and contain 1 0 pierced plates. Fresh caustic solution at an ambient temperature containing 7%-l0% NaOHis used vand this'solution is preferably used once-.through and discarded to spent caustic tankage ata .level of 5% to 10% spent; that is, lit contains 5 %-8% free NaOH. .Such a scrubbing system .has ybeen found to result in a feedto the subsequent.polymerizationplantcontaining as vlow as 2-5p. p. m. of sulfur andthe resulting C7 olen produced in 4said plant has contained 3-10 p. p. m. of sulfur.

The C3 and C4 streams, now containing less than about l0 p. p. m. of sulfur,.are passed Ainto polymerization unit 5 whereinthe olefins are polymerized in the vpresence of .a lcalc ined phosphoric acid-kieselguhr catalyst. The ,re action conditions within polyrnerization plant 5, which .may be operated Yin-one or more stages, includcltemperatures of about S80- 500 E., pressures of =200-1200 s. i. g., land feed `rates of 0.5-6.0 volumes liquid/vol. reactionspace `per hour. The yratio of C3 to normal YAolefin -may Ybe l' to 2/ l.

lThe total polymerizate from unit 5 is passed via line 6 to still 7. Light material is takenoverhead as a heads cut through line 8. The heart cut, corresponding to the heptene fraction, is withdrawn through line l0. This .fraction boils in the rangeof about 15T-.210 F. at at- Ltnospl'leric pressures, and has a Yheptene .content .otqabout 2815-100270." As .will be developed below in an alternate embodiment of thepresent invention, volatilities of impurities in still 7 may be controlled by .distillation ad- 'juyants introduced through line 9.

The clelin is passed through line 10 and is pumped to preheater 18 wherein it is brought to the desired temperature range and then discharged via line 20 tothe bottom of primary c arbonylation reactor 22. Suitable catalyst, ,s uch as cobalt oleate naphthenateand @the Vlike is added through line 24 in ,such proportions that the Weight of cobalt in solution is about 0.l-0.3%f.9 f.the total liquid. Reactor 22 comprises a high pressure lreactor vessel which may, if desired, be packed with non-catalytic material such as ceramic rings, porcelain or quartz chips, pumice and the like. It may also be divided into discrete packed zones separated by any suitable means, such as support grids, etc. or it may comprise but a single packed zone, or it may contain no packing.

A stream of synthesis gas comprising H2 and CO in the approximate ratio of 0.5-2 volumes Hz/CO, preferably 1.0l.2 to 1, is fed into reactor 22 through line 38. The synthesis gas stream is a composite of fresh gas and recycle, and ilows upwardly with the Iolefin feed through reactor 22. The latter is preferably operated at a pressure of about 250G-3500 p. s. i. g. and at a carefully controlled temperature range of 300-375 F., preferably between 340-360 F. The rate of flow of synthesis gases and of olefin through reactor 22 is so regulated that the desired conversion level of olefin is obtained. These conditions include an olen fresh feed rate of about 0.3- 1.0 v./v./hr., fresh synthesis gas feed rates of 100G-10,000 cubic feet/barrel of olefin, catalyst concentration of 0.1- 0.3% cobalt based on olen feed, and a nominal residence time of about 1-3 hours.

The carbonylation reaction may be carried out substantially adiabatically, that is, no external cooling means such as tubes or coils need be provided, but cooling and temperature control of the highly exothermic reaction is carried out by recycle of a portion of the product, as described below. Liquid oxygenated reaction products containing catalyst in solution, as well as unreacted synthesis gases are withdrawn from an upper portion of high pressure reactor 22 and transferred through line 26 and cooler 28 to high pressure separator 32 where unreacted gases are withdrawn yoverhead through line 34, scrubbed in scrubber 36 of entrained liquid, and preferably recycled to reactor 22 via line 38. Make up synthesis gas may be admitted through line 39. A portion of the recycle may be purged through line 40 to maintain the desired Hz/CO ratio in the feed.

Liquid carbonylation product containing dissolved therein relatively high concentrations of cobalt carbonyl is withdrawn from separator 32 via line 42. A portion of this stream may be recycled to reactor 22 via line 44 to aid in the cooling and maintenance of temperature control of the primary carbonylati'on stage. Preferably recycle liquid product is injected at various levels within reactor 22 to obtain close temperature control throughout the whole reactor. Approximately 400-500 volume percent of liquid reaction product on the fresh olein feed may be recycled for this purpose. The temperature of such recycled material is generally dependent on that of the atmosphere, and may be about 30-1G0 F.

The balance of the primary reaction product not recycled to reactor 22, which may comprise, beside desired octyl aldehydes, a-lso unreacted oleiins, secondary reaction products, and dissolved cobalt carbonyls, is withdrawn through pressure release valve 46 and line 48 and passed to decobalting zone 50. Within decobalter 50, soluble cobalt carbonyl is removed from the aldehyde product prior to high pressure hydrogenation in order to prevent its decomposition in the subsequent hydrogenation stage with consequent fouling of coils and reactor plugging. The decomposition of the cobalt carbonyl is obtained by heating the aldehyde product by such means as steam coils, etc. to about 30G-350 F. at a pressure just high enough to keep the components in the liquid phase. Pressures in the neighborhood of 100-150 p. s. i. g. are preferred. The product containing catalyst in solution is injected into decobalter 50 through line 48 and stripping gas, such as Hz may be added through line 52 to aid in decreasing the CO partial pressure. If desired, it may be advantageous to operate with two or more decobalters, switching the stream from one to the other as the one in service accumulates excessive quantities of cobalt metal. The gas stream comprising stripping gas and CO may be removed overhead from 50 through line 54 and used as desired. Other means of decobalting, such'asby steam, water, or acid, may also be employed.

f, The liquid aldehyde producty now substantially free of dissolved catalyst is withdrawn from 50 through line 56 and passed through filter 58 for removal of any suspended cobalt. The filtered solution is withdrawn from 58 and passed through preheater 60 to the bottom portion of hydrogenation reactor 64 via line 62. Simultaneously, hydrogen is supplied to 64 in proportions more than suficient to convert the aldehydic product into octyl alcohols. Hydrogenator 64 may contain a mass of any conventional hydrogenation catalyst, such as nickel, copper chromite, sulfactive catalyst such as tungsten, nickel or molybdenum sulde, preferably supported on carriers such as purnic'e, charcoal, etc. Reactor 64 is preferably operated at temperatures of about 300-500 F. and pressures of about Z500-3500 p. s. i. g. 'v

The products from the hydrogenation reactor and unreacted hydrogen may be withdrawn overhead through line 68, passed through cooler 70 and high pressure separator 72, whence excess H2 is removed overhead through 74 for recycle. The liquid product is withdrawn from separator 72 through line 76 and, after passing through conventional low pressure separators and stabilizers (not shown), isv passed to hydrocarbon still 78, wherein are distilled overhead low boiling products, mostly hydrocarbons boiling below 356 F. These materials are removed through as a heads cut and may be used as gasoline blending agents. The bottoms from this primary distillation are withdrawn from hydrocarbon still 78 via line 82 and sent to alcohol still 84 where an octyl alcohol cut boiling within the range of 356 to 392 F. at atmospheric pressures is taken. However, if desired, it may be desirable to distill alcohols at reduced pressure. The alcohols are `withdrawn overhead from still 84 through line 86 and sent to storage tank S8, from whence they are sent to an esterication plant for conversion into a di-octyl ester, such as di-octyl phthalate, all in a manner known per se. High boiling bottoms from 84 may be withdrawn through line 90 and may be used in any desired manner, such as cracking stock, fuel, etc., or they may be further processed and distilled at subatmospheric pressures to recover valuable oxygenated organic products.

In accordance with the present invention, substantially sulfur-free alcohols, or an alcohol product containing less than about 10 parts per million, may be produced.

To show that high ester color is directly associated with sulfur content, the following data. are presented. In the first series of experiments, synthetic mixtures of mercaptans and octyl alcohols were prepared, while in the second series, plant alcohol samples were analyzed for sulfur content and ester color.

P. P. M. Sulfur Ester Color 4,470 A.

N-heAptyl mereaptan in 2-ethyl hexanolthe alcohol and the corresponding ester color.

Ester Sulfur in Sulfur in C1 Feed, P. P. M. Color Alcohol,

P. P. M.

0.10 2 0.14 4 0. 20 1o-15 o. 2s 15-25 0. as 20-30 This correlation between sulfur in the feed and in the alcohol, and ester color is to a certain extent variable, depending upon the type of sulfur present in the respective feed and alcohol, but `the above data have been Desulfurlzaton of C7 UOP olens Test Conditions Results 1 Copper on Alumina 300 F., Feed-:1143 p. p. rn. S., Product U p`. S`. g. 7-511 p. p. 11'1. S. 2 Copper on Alumina 300 F., Feed 99 p. p. m. S., Product 100 100 n. s. i. g. 30G-a, 700 15 p. p. m. S., 10% Loss of Lt. E. (Hydrogen Added). Ends and Polymer.

3 UOP Nickel, 20D-250 F-.. Y Feed 98 p. p. m. S., Product 39-16 p. p. m. Loss in activity to 68 p. n. m. S. at end of run pu 7-14% of olen hydrogena e 401)--. Iron Rust Feed 61 p. p. m. Product 46 p.A p. m. 4(b) Iron Rust, Room Tempera- Feed=35 p. p. m., Product 35 ture. p. p. m. 5 Resin IRA-400, 1 v./v./hr. Feed=35 p. p. m., Produet=34 Room Temp. p. p. m. 6 Charcoal,1v./v./hr.@Room Feed=30 p. p. m., Product=33 Temp. p. p. n1.

7 5% NaOH or 10% NaOH. Feed=30 p. p. m., Product=36 p. p. m.

8 Mercurous Nitrate, 1% as Feed=30 p. p. m., Product= 1 Solid (Analytical Method) p. p. m. (for Thioethcr).

`From these data it can be readily seen that the only eiective method has been treatment with mercurous nitrate, the use of which would be prohibitive on a commercial operation. lt is also seen that caustic treating of the oleiin feed to the Oxo stage with 5% or even 10% sodium hydroxide gave no improvement whereas similar treatment of the feed to the polymerization unit gave substantial decrease in the sulfur content of from 25 p. p. m. to as low as 2-5 p. p. m.

In another embodiment of the present invention, small amounts of certain distillation adjuvants are added to the polymer distillation zone through line 9. Thus, any mercaptans not removed in scrubbers 3 and 4 react in unit 5 to form higher mercaptans or thioethers. In the distillation zone 7, those sulfur compounds having the same boiling range as the C7' oleins, or which azeotrope with them, would be withdrawn with the Oxo feed stream. L In accordance with one embodiment of the invention, a

Small amount of strong H2804 of 70-9370 strength, is continuously admitted through line 9, to the extent of less than 5%, and preferably 0.1-1.0 wt. percent of feed. The passage ot the acid downwardly through the tower seives to depress the volatility of sulfur compounds contained in the feed to the tower. The acid provides formation of loose molecular complexes with mercaptans and thioethers, and thus any such present in the tower are withdrawn through line 11i., together with H2804 and higher boiling oletins. Any mono and dialkyl sulfates formed in tower 7 are also eective in reducing the relative volatility of thioethers and mercaptans present.

Instead of H2804, the relative volatility of any mercaptans and thioether's present in still '7 may also be repressed by adding, in amounts less than 5% on feed, and preferably 0.1 to 1.0%, certain alkaline reacting materials. Thus, metal hydroxides, as those of Na, K, Ba, etc.,'may be employed which may be solubilized by addition of high boiling alcohols or phenols, etc. Also,

CIV

organic amines or alkanol amines boiling above the olefin cut to be taken overhead, such as triethanolamines, aliphatic amines, and the like may be employed as volatility repressing agents for organic sulfur compounds. Metal alcoholates and phenolates are also suitable.

The process of the present invention may be subject to many modifications without departing from its spirit. In its broadest aspect, it incorporates the discovery that even extremely small traces of sulfur are deleterious for preparation of high quality Oxo alcohols. Thus, besides the C3, C4, and C7 fraction, other olefin fractions may be treated to reduce their sulfur content below about p. p. m. prior to being employed in the alcohol synthesis process. Besides caustic treating of the light ends streams to the polymer plant, other means of removing sulfur compounds, such as treatment with diethanolamine, lime, solubilized caustic solutions, such as the Sodasol or the Unisol processes may be employed. Also, other olefins such as those resulting from wax or petrolatum crac-king and from hydrocarbon synthesis, may also be made suitable fo'r the production of plasticizing alcohols and esters by the process of the invention.

What is claimed is:

1. An improved process for producing alcohols which comprises passing at least a single hydrocarbon stream rich in low molecular Weight normally gaseous oletinic compounds and contaminated with minor amounts of sulfur compounds to a sulfur removal zone, scrubbing said hyd-rocarbon stream with 'an alkaline treating agent in the s'ultur removal zone, withdrawing from said sulfur removal Zone prior to polymerization an olenic stream substantially reduced in sulfur content and containing no more than about l0 parts per million of sulfur compounds, passing said stream to a polymerization zone, contacting said stream with a light olen polymerization catalyst to produce a liquid polymeric oleinic mixture, separating a C7 olefin containing fraction of said oleiinic mixture, passing said fraction to a carbonylation zone, treating said separated fraction in said zone with CO and H2 in the presence of a cobalt catalyst at elevated temperatures and pressures whereby an aldehyde product is formed, reducing said aldehyde product in a hydrogenation zone and recovering an alcohol product of superior properties.

2. The process of claim 1 wherein said stream passed to said sulfur removal zone contains at least l() parts per million of ethyl mercaptan and said stream withdrawn from said zone less than 10 p. p. m. of ethyl mercaptan.

3. A process according to claim 1 wherein the polymerized oleiins are distilled in the presence of sulfuric acid of 70 to 98% strength as a distillation adjuvant.

4. The process of claim l wherein said sulfur removal zone contains an aqueous dilute solution of caustic, said caustic being present at a concentration level of not substantially greater than about 10%.

References Cited in the le of this patent UNITED STATES PATENTS 2,558,137 Hepp June 26, 1951 2,595,763 Carlson et al. May 6, 1952 2,625,527 Smith et al. Ian. 13, 1953 2,658,932 Cohen et al. Nov. 10, 1953 2,700,687 Catterall v Jan. 25, 1955 OTHER REFERENCES I. G. Farben patent application I 72, 975 IVD/ 120, O. Z. 13604, published in T. C. M. Reel 36 item 2l and part of item 36, pgs. and 51, March 12, 1946 available in translation PC-S-V by Charles Meyer and Co. 

1. AN IMPROVED PROCESS FOR PRODUCING ALCOHOLS WHICH COMPRISES PASSING AT LEAST A SINGLE HYDROCARBON STREAM RICH IN LOW MOLECULAR WEIGHT NORMALLY GASEOUS OLEFINIC COMPOUNDS AND CONTAMINATED WITH MINOR AMOUNTS OF SULFUR COMPOUNDS TO A SULFUR REMOVAL ZONE, SCRUBBING SAID HYDROCARBON STREAM WITH AN ALKALINE TREATING AGENT IN THE SULFUR REMOVAL ZONE, WITHDRAWING FROM SAID SULFUR REMOVAL ZONE PRIOR TO POLYMERIZATION AN OLEFINIC STREAM SUBSTANTIALLY REDUCED IN SULFUR CONTENT AND CONTAINING NO MORE THAN ABOUT 10 PARTS MILLION OF SULFUR COMPOUNDS, PASSING SAID STREAM TO A POLYMERIZATION ZONE, CONTACTING SAID STREAM WITH A LIGHT OLEFIN POLYMERIZATION CATALYST TO PRODUCE A LIQUID POLYMERIC OLEFINIC MIXTURE SEPARATING A C7 OLEFIN CONTAINING FRACTION OF SAID OLEFINIC MIXTURE, PASSING SAID FRACTION TO A CARBONYLATION ZONE, TREATING SAID SEPARATED FRACTION IN SAID ZONE WITH CO AND H2 IN THE PRESENCE OF A COBALT CATALYST AT ELEVATED TEMPERATURES AND PRESSURES WHEREBY AN ALDEHYDE PRODUCT IS FORMED, REDUCING SAID ALDEHYDE PRODUCT IN A HYDROGENATION ZONE AND RECOVERING AN ALCOHOL PRODUCT OF SUPERIOR PROPERTIES. 